CONDENSACION ALDOLICA CRUZADA PDF

May 1, 2019 posted by

como nucleofilo en el carbono del benzaldehído, realizando una reacción de condensación de Claisen-Schmidt (tipo de condensación aldolica cruzada). Particulares ○ Efectuar una condensación aldólica cruzada. ○ Obtener un producto de uso comercial. Diferencia entre una condensación aldólica cruzada y. Específicos Efectuar una condensación aldólica cruzada. Determinar el rendimiento de la reacción realizada y el punto fusión del producto obtenido.

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Recientemente, el TMP ha empezado a ser ampliamente utilizado y particularmente en cruazda uso como materia prima para resinas curables con ultravioleta, presentando el TMP una pureza superior a la que antes se ha llegado a requerir.

Then, after further adding The present invention coneensacion further explained by reference to the following examples which should not be construed as limiting the scope of the present invention. Sin embargo, de manera perjudicial el color fundido del TMP final fue tan elevado como Therefore, an object of the present invention to provide an industrially advantageous method for producing a highly pure TMP from a crude TMP cruzadaa by a reaction between NBAL and formaldehyde in the presence of a basic catalyst in a two-phase condensation aldol and a subsequent crossed Cannizzaro reaction.

However, when TMP contains the formic acid condensscion and the component of high boiling condensation products are decomposed hard by heat treatment in the presence of acid even in an amount equivalent to the amount of formic acid saltleaving obtained this a highly pure TMP mode.

TMP obtained by purification of crude TMP by the method of the present invention has such a high purity as After removing the component and high boiling inorganic salt of crude TMP, the resultant TMP distillate is subjected to a heat treatment under acidic conditions. Formaldehyde used in the cruzafa invention as starting material can be used as an aqueous solution or solid as paraformaldehyde.

The content of the remaining formaldehyde in the final TMP was 30 ppm. The first stage aldol condensation and the cruazda stage crossed Cannizzaro reaction are usually conducted successively in the same reaction vessel, without differentiating from the operational point of view one another. Ejemplo comparativo 2 Comparative Example 2.

Masters and doctoral program in Chemical Sciences

Deactivation is carried out by adding the acid to the crude TMP in an amount 0. In the present invention, it is not necessary to use expensive cation exchange resins, etc. The Japanese Patent Publication No. For an industrial process, the sodium or potassium salts are preferred. In addition, a highly pure TMP is obtained, since the remaining formaldehyde condenses with TMP is to form easily removable CMF during one heat treatment under acidic conditions.

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Por tanto, se produce a escala industrial de manera ventajosa un TMP sumamente puro utilizable como materia prima para resinas curables con ultravioleta. A process for obtaining trimethylolpropane-enriched product streams from the secondary streams of trimethylolpropane.

File:Cuatro productos reacción aldólica cruzada.svg

Therefore it occurs industrially advantageously a highly pure TMP usable as a raw material for ultraviolet curable resins. The impurities are free formaldehyde, condensation products of TMP and formaldehyde, methanol contained in formalin starting, methanol formed during the crossed Cannizzaro reaction, condensation products aldolcia methanol, TMP and formaldehyde, etc.

In the method known in the art, the liquid reaction mixture is distilled after removing most of the formic acid salt by a solvent extraction or a hot filtration after condensing and TMP distillate resulting crude is rectified to obtain thereby a final TMP with a high purity. A method of further purification is described in DD-A Ejemplo comparativo cryzada Comparative Example 1.

The method proposed in Japanese Patent Publication No.

Method for producing a highly pure trimethylolpropane condendacion to claim 1, wherein component removing high boiling point and the inorganic salt is carried out after deactivating sodium formate present in the crude trimethylolpropane, wherein the deactivation is carried out by means of adding an acid to crude TMP in an amount 0.

However, since TMP after the solvent extraction, the hot filtration, etc. To minimize the occurrence of byproducts and increase selectivity of the objective TMP, preferred set the amount of the basic catalyst according to the reaction conditions. The present invention has been accomplished based on this finding. The content of the remaining formaldehyde in the final TMP was 1 ppm. The content of the remaining formaldehyde in the final TMP was condensaciln ppm.

In addition, formaldehyde remaining in TMP product is not the completely eliminated by a usual distillation. The gas chromatographic analysis showed that the purity of TMP obtained was The content of the remaining formaldehyde in the final TMP was 5 ppm. Although the condensation products are decomposed by the alodlica treatment using excess amount of acid, a colored component from high boiling point, which is difficult to remove TMP by distillation component is formed.

In the following examples and comparative examples, the content of the remaining formaldehyde in the final TMP product was determined by acetylacetone method, and the color cast APHA color pattern obtained according to JIS K document 6. In the present invention, before the subsequent heat treatment, a component of high boiling point and an ctuzada salt, including the salt of residual formic acid akdolica as a byproduct during the crossed Cannizzaro reaction, the TMP crude thus separated was previously removed.

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The solvent may be used alone or in combination of condeensacion or more.

The purity of TMP obtained was The final product quality is adversely affected by the remaining formaldehyde even in a small amount. The present invention relates to a method of purifying a crude TMP obtained by an aldol condensation and a subsequent crossed Cannizzaro reaction of NBAL of formaldehyde in the presence of a basic catalyst.

With such heat treatment, the component hardly removable from TMP by distillation is thermally decomposed or chemically combines to form an easily removable component of TMP by distillation. Thus, a highly pure TMP has not been obtained with conventional distillation methods. For example, the two-phase process using sodium hydroxide is expressed by the following reaction scheme.

Condensação de Claisen

The product mixture from the reaction of NBAL and formaldehyde is separated, if necessary after removing formaldehyde unreacted by condensation in crude TMP and the formic acid salt, obtained as a byproduct during the crossed Cannizzaro reaction by a solvent extraction or hot filtration after condensing.

Such an acid may include mineral acids such as phosphoric acid and sulfuric acid and organic acids such as p-toluenesulfonic acid and methanesulfonic acid. Para un procedimiento industrial, se prefieren las sales de sodio o potasio. Ejemplo comparativo 4 Comparative Example 4. To completely remove the impurities such as formaldehyde, MDF, etc. Trimethylolpropane hereinafter referred to as “TMP” has been produced by a known two-stage process see for example, DE-A comprising an aldol condensation between n-butyl aldehyde hereinafter referred hereinafter as “NBAL” and formaldehyde in the presence of a basic catalyst and a subsequent crosslinking reaction between the aldol condensation product and formaldehyde in a basic catalyst Cannizzaro.

In the present invention, as described above, after first removing the inorganic salt such as sodium formate, and the component of high boiling the crude TMP, the treated TMP is subjected to heat treatment under acidic conditions. Ejemplo comparativo alodlica Comparative Example 3. Purification of propylene oxide using crkzada aqueous acetone extractive distillatin agent. In the present invention, as the load of distillation column is reduced, the distillation apparatus improved from the economic viewpoint with respect to the structure and operatively allowing it to produce a highly pure TMP advantageously in industrial scale.

A process for the decomposition of polyhydric alcohols in the synthesis of high-boiling by-products formed.